HOST RESPONSE TO ANTIGENIC ACTION 449 



tic action of the glucoside disappeared within two hours after in- 

 jection and, in order to elicit the phenomenon, the carbohydrate 

 had to be the same as that combined in the sugar-protein complex. 



PASSIVE SENSITIZATION 



From the collective experience of immunologists it becomes evi- 

 dent that some of the isolated constituents of the pneumococcal 

 cell are incapable of so sensitizing the guinea pig as to render the 

 animal susceptible to anaphylactic intoxication upon the paren- 

 teral introduction of Pneumococcus or its derivatives. However, 

 that an animal may be rendered highly sensitive to pneumococcal 

 substances by the injection of specific antipneumococcic serum is 

 supported by ample evidence. Weil and Torrey 1508 passively sensi- 

 tized guinea pigs by the injection of serum from pneumonia pa- 

 tients. When autolysates of pneumococci were added to the uterus 

 of the treated animal, positive contractions occurred only when 

 the serum employed originated from a case of pneumococcal pneu- 

 monia. By means of the same method, Zinsser and Mallory 1582 ob- 

 tained positive reactions with the uteri of guinea pigs passively 

 sensitized with antipneumococcic serum. More conclusive were the 

 observations of Tomcsik (192T), 1415 who demonstrated the ability 

 of the soluble specific substance of Pneumococcus to produce ana- 

 phylactic shock in passively sensitized guinea pigs. The purified 

 capsular polysaccharide of Pneumococcus, though apparently de- 

 void of sensitizing action, can induce rapid and fatal anaphylactic 

 shock when injected intravenously into guinea pigs passively sensi- 

 tized with the precipitating serum of rabbits actively immunized 

 with pneumococci of the homologous type, the reactions induced 

 being type-specific. Avery and Tillett, 60 who reported the observa- 

 tion, also drew attention to the fact that there was a complete ab- 

 sence of anaphylactic response to pneumococcal carbohydrate in 

 guinea pigs similarly treated with antipneumococcic horse serum. 



As in their experiments on the production of active specific 

 sensitization with artificially prepared sugar-proteins, Tillett, 



